/*
 * Copyright 2016-2024 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.vault.authentication;

/**
 * Interface to obtain a UserId for AppId authentication. Implementations are used by
 * {@link AppIdAuthentication}.
 *
 * @author Mark Paluch
 * @see AppIdAuthentication
 * @deprecated since 2.2. Use {@link AppRoleAuthentication}.
 */
@Deprecated(since = "2.2", forRemoval = true)
@FunctionalInterface
public interface AppIdUserIdMechanism {

	/**
	 * Create a UserId for AppId authentication.
	 * @return the UserId.
	 */
	String createUserId();

}
